
<p>The HTTP scheme (i.e. http, https).  Evaluated only on demand, for example:
</p>
<pre class="code"><span class="kw22">rewrite</span>  ^<span class="br0">&#40;</span>.+<span class="br0">&#41;</span>$  <span class="re0">$scheme</span>://example.com$<span class="nu0">1</span>  redirect;</pre>
